NONLINEAR CONDUCTION IN THE SPIN-DENSITY-WAVE PHASE OF (TMTSF)(2)ASF6

We observed the current-voltage relation in the spin-density wave (SDW ) phase of slightly pressurized (TMTSF)(2)AsF6 above 0.6 K to investig ate the SDW dynamics. In the entire temperature range below a transiti on temperature of similar to 10 K, the ohmic and non-ohmic regions are clearly distinguished by the well-defined threshold electric field. T he SDW dynamics show anomalies at similar to 3 K and, only below simil ar to 3 K, ''transient voltage oscillation'', ''narrow band noise'' an d dielectric voltage response for constant pulse current can be observ ed. In (TMTSF)(2)PF6, the sub-phase transitions at similar to 3 K and similar to 1 K have been reported. Relations between the SDW dynamics and the sub-phase transitions are discussed.